The Greek scientist Theophrastus wrote The Causes of Plants and The History of Plants, initiating the study of botany.

Peri phytikon historion (translated in Enquiry into Plants and Minor Works on Odours and Weather Signs, 1916; often designated by the Latin title, De historia plantarum) and Peri phytikon aition (partial translation in De Causis Plantarum, 1976) are the earliest substantial works of botany written in ancient Greek. They are most commonly referred to as The History of Plants and The Causes of Plants. Together they provide a full system of botany. Although earlier writers often focused only on the dietary or medicinal value of plants, Theophrastus was interested in plants as a form of knowledge. The History of Plants provides descriptions and contains nine books. In the first book, he considers general issues such as identification of the parts of plants and their division into tree, shrub, undershrub, and herb. The remaining books treat particular issues: the growth and care of domestic trees, wild plants, trees and plants of distant places, the timbers and their specific uses, shrubs, herbaceous plants, saps, and medicinal uses of plants. The Causes of Plants treats physiology and consists of six books: how plants come into being, including grafting and budding; how the environment affects plants; how culture affects plants; how cereals originated and became cultivated; unnatural influences, including disease and death; and the odor and taste of plants. Theophrastus

Discussion of around 550 plant species and varieties native to the regions between the Atlantic and India appears in these works. Theophrastus’s sources include poets, philosophers, and especially Empedocles (c. 490-c. 430 b.c.e.) and Democritus (c. 460-c. 370 b.c.e.)—pre-Socratic philosophers who had written about plants. He also records the beliefs and practices of those native to the regions in which particular plants grew, such as farmers, physicians, and root-cutters. In addition, he includes oral reports, technical writings, and even the notes of companions of Alexander the Great who studied plants for their military significance. Although it might seem “unscientific” to present travelers’ tales and even superstitions in a scientific work, such was the practice even into the eighteenth century. Moreover, Theophrastus often cautions the reader that further investigation was necessary.

Theophrastus, as portrayed on the cover of a seventeenth century botanical book.

(Library of Congress)

Originally named Tyrtamus, Theophrastus was born in Eresus on the island of Lesbos. According to Diogenes Laertius, he studied first with Alcippus, then with Plato, and finally with Aristotle, who renamed him Theophrastus (he of the godlike speech) because of the divine way in which he spoke. When Aristotle retired to Chalcis in 322 b.c.e., Theophrastus assumed leadership of the Lyceum, attracting two thousand students during the course of his long life.

Theophrastus in the main accepted Aristotle’s metaphysical assumptions, though he did question their application. In particular he doubted Aristotle’s reliance on teleology, or the idea that everything has a purpose. In the heavens, but more particularly on Earth, coincidence or necessity seems to characterize events, such as the birth and nutrition of animals. As phenomena vary in the degree to which they manifest order, Theophrastus argued that there must be different ways of knowing things. Reason knows first principles, for example, while the senses know the causes of natural objects, such as inanimate things, animals, and plants. On the other hand, Aristotle had employed the methods of observation, and Theophrastus’s botanical works parallel Aristotle’s Ton peri ta zōa historiai (c. 348-346 b.c.e.; Zoology, 1812) and Peri zōōn moriōn (c. 335-323 b.c.e.; On the Parts of Animals, 1882). The empirical aspect of Aristotle’s thought appealed greatly to Theophrastus. Although Theophrastus did recognize analogies between plant and animal, he realized their limitations. Furthermore, he recognized the difficulties of generalizations about plants because, as a whole, they do not all share parts in common. Plants without roots, stem, flowers, or other parts exist. Thus, there is a method of knowledge unique to plants. The object of study was therefore not the universal but the particular, grounded in sense perceptions and not in reason.

Although Theophrastus is often called the “father of botany,” he, like his teacher Aristotle, was interested in a wide range of subjects, both philosophical and scientific. Diogenes Laertius lists 224 titles authored by Theophrastus, including works on logic, metaphysics, ethics, law, medicine, religion, mathematics, the natural sciences, and earlier philosophers, totaling 232,850 lines. Other than the two botanical books, only a few short scientific treatises; an essay on metaphysics; the Characteres ethikoi (c. 319 b.c.e.; The Moral Characters of Theophrastus, 1702, best known as Characters), which illustrates Aristotle’s moral types; and fragments or summaries of a few other works exist today.

Theophrastus’s observations led to many distinctions that form the foundation of the science of botany. Although he did not use the modern terms, he recognized the differences between parenchymatous and prosenchymatous tissues; between petalous and apetalous flowers; among hypogynous, perigynous, and epigynous insertions of the corolla, between angiosperms and gynmosperms; and between monocotyledons and dicotyledons. Some of his accounts, such as that of germinating seeds, reveal careful personal observation. Ideas from his botanical works may have found their way into Arabic commentaries, and in the late fifteenth century the first two Latin translations of these works appeared. The plant descriptions of Otto Brunfels (1488-1534) and Leonhard Fuchs (1501-1566) used word-for-word translations from the works of Theophrastus and other ancient botanists.

• Fortenbaugh, William W., Pamela M. Huby, and Anthony A. Long, eds. Theophrastus of Eresus: Sources for His Life, Writings, Thought, and Influence. 2 vols. Leiden, the Netherlands: E. J. Brill, 1993. The first scholarly effort in more than a century to collect all the historical documents—text, translations, and commentary—on the fragments of and testimonies about Theophrastus. A collection of articles on a wide variety of Theophrastus’s works, including pieces on teleology and the transmission of his works into Arabic.
• Greene, Edward Lee. Landmarks of Botanical History. Part 1. Edited by Frank N. Egerton. Stanford, Calif.: Stanford University Press, 1983. Written in the late nineteenth century, this reissued work presents a long chapter on the botany of Theophrastus arguing that his works were the basis of the botany of the sixteenth century.
• Sharples, R. W. Theophrastus of Eresus: Sources for His Life, Writings, Thought, and Influence. New York: E. J. Brill, 1995. Presents a short overview of Theophrastus’s botanical works and comments on the doxographical references to these works.
• Theophrastus. Metaphysics. Translated, with an introduction and commentary, by Marlein Van Raalte. New York: E. J. Brill, 1993. A translation that includes an extensive analysis of its passages, especially Theophrastus’s views on teleology.

Anaxagoras; Anaximander; Archimedes; Aristotle; Democritus; Empedocles; Pliny the Elder; Theophrastus. Botany, study of